My question if focused on your statement "you have to be willing to hike to experience and appreciate all of its beauty, not just drive..."
The problem is, that's not possible for families who travel with very little children and/or babies.
Hence my question to you and to everyone else here who's been to many NPs like you. Can you please list your top ten or twenty NPs (or even state parks for that matter, if they're nice enough), in order of your favorites, but specifically keeping in mind someone who can't go on any long or strenuous hikes, or any hikes impractical or unsafe for small children.
With that in mind, would Glacier still be your favorite? Or would that alter your order of preference entirely?
...
I'd like to go back to most of them, though Glacier is also high on my list. But at this point in life it's gonna have to be with little kids in tow.
Out of the 30 National Parks I've been to, 25 have been with kids 5 and under. We just don't do long hikes, and that's fine...
Many moons ago, when I was in my early 20s (pre-kids), we did a ranger-guided hike to Iceberg Lake in Glacier National Park. That's a 7-hour roundtrip hike, mostly uphill on the way there, mostly downhill on the way back. The most memorable part was the knee pain on the way back. Each step downhill sent shooting pain to my knees. When we got back to the car, I wanted to sit for a year. In retrospect, we were in terrible shape and should not have done the hike. Having young kids actually keeps us from doing hikes we are not prepared for.

My new approach to hiking is that the payoff has to be something truly unique. 7 hours to hike up close to lava, I'll get through it somehow. 7 hours for a view? Not a chance.
To answer your question, here are some NPs with nice hikes even kids can do/other activities for kids:
Indiana Dunes NP | sand dunes |
White Sands NP | sand dunes |
Great Sand Dunes NP | sand dunes |
Carlsbad Caverns NP | cave |
Mammoth Cave NP | cave |
Wind Cave NP | cave |
Hawai'i Volcanoes NP | lava tube/cave |
Sequoia NP | hike to the General Sherman tree |
Olympic NP | Hall of Mosses, beaches |
Grand Canyon NP | walk up to great views |
Yellowstone NP | lots of short walks on boardwalks |
Bryce NP | short walk among hoodoos |
Almost all national parks have ranger-led activities that are appropriate for kids.
I have a friend that runs the Grand Canyon rim-to-rim-to-rim every year as a birthday present to himself, so he likes long hikes. When his son was a year old, they did a cross-country road trip hitting up about 20 national parks. He carried his son in his arms everywhere, so obviously no long hikes, but they still managed to see and enjoy quite a bit.